Quoting White Chocolate Milk:" If he does it himself it is fine. Just continue to put him down on his back and just let him sleep how ... [snip!] ... his head and you don't have to worry about him suffocating. Just make sure the crib is clear of blankets and stuffed animals."
Quoting Saelym:" Ok thanks ladies! I know if he rolls while he is sleeping there isn't really anything I can do, I can't ... [snip!] ... pads on the crib because he got his legs/arms stuck a couple times one night and screamed. No blankets or anything in there! "